Topic: 22r piston height question

[chenkthetank]

background:
I recently picked up an 85 pickup with a recently rebuilt motor.

drove it home could not keep it running at 0* timing with the assist capped off.

from there i did a compression test:

#1 89psi
#2 89psi
#3 90psi
#4 88psi
these number were pretty much identical dry/wet, they might have moved a little but not enough to measure/not be tool error.

so then i check all the valves, all were in spec.

also i verified TDC was at 0 on the crank timing and everythign lined up where it should.

so from there i assumed the head must be bad, which im still going to have it tested while i have it off, but when i took it off i noticed something.

The block does not have the laser mark/mickymouse and the head does not have oval exahaust ports, so im 99.9% its an 84 22r, yet the pistons used in the rebuild are not domed and they dont come up to the top of the block:




just does not seem correct to me, but through searching google/yotatech/bulid threads i can not find a definitive answer if i need to pull those pistons and get some for the 84 block.

If i do need to pull the pistons, can i just get some that are .2 over for and 84 and rehone the cylinders, or do i need to drop the block and have a machine shop bore it to the piston?

THanks for any help you can give.

[brainlessfool]

I do not beleve that pistons for a 85 are domed. there dished. and the head should have a smaller cc.
my 83 has a open camber head and the stock pistons where flat.

[heep70]

Sounds like you have a 22R tall block with 22RE rods.  There is a 2mm difference between a 22R and a22RE block deck height if I remember right.  The pic is a 84' block with stock full brow pistons.  The pistons are pretty much level with the deck (not the brow portion).  The dial indicator is measuring TDC of the piston.   Also sounds like your compression is way low on all holes.  

[chenkthetank [OP]]

Thank you for that pic heap, that settles it I have the wrong pistons.